David Humphreys is an Associate Professor of Evidence-Based Intervention and Policy Evaluation. He is an interdisciplinary social scientist whose research spans several fields including:, criminology, social (or public) policy, public health, and epidemiology. His main topic of interest focuses on the causes, consequences and prevention of violence and injury. Much of his research investigates how structural changes—such as laws, regulations or changes to the built environment—impact on the rate and/or distribution of harm in the population.
David’s research typically utilises observational or non-randomised research designs. As a consequence, his research and teaching bring together an interest in methodological aspects of intervention research, such as: the design of complex interventions (natural and quasi-experiments); the measurement of physical harms and its related environmental exposures; and the assessment and synthesis of equity effects.
He joined the Department in October 2013, having previously held research positions at the Institute of Public Health and the Institute of Criminology at the University of Cambridge. He completed his doctorate at the Institute of Criminology, at the University of Cambridge, in 2011.
David has affiliations with the Violence Research Centre at the University of Cambridge and is affiliated with the Penn Injury Science Center at the Perelman School of Medicine at the University of Pennsylvania. He has held research grants from the NIHR, ESRC and the Joyce Foundation, among others.
Intimate partner violence victimisation in early adulthood: psychometric properties of a new measure and gender differences in the Avon Longitudinal Study of Parents and Children.
2019
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Journal article
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BMJ Open
OBJECTIVES: To evaluate the psychometric properties of a novel, brief measure of physical, psychological and sexual intimate partner violence (IPV) and estimate the overall prevalence of and gender differences in this violence. DESIGN: Data are from the Avon Longitudinal Study of Parents and Children (ALSPAC), a birth-cohort study. SETTING: Avon, UK. PARTICIPANTS: 2128 women and 1145 men who completed the questionnaire assessment at age 21. OUTCOME MEASURES: Participants responded to eight items on physical, psychological and sexual IPV victimisation at age 21. Participants indicated whether the violence occurred before age 18 and/or after and led to any of eight negative impacts (eg, fear). We estimated the prevalence of IPV and tested for gender differences using χ2 or t-tests. We evaluated the IPV victimisation measure based on internal consistency (alpha coefficient), dimensionality (exploratory factor analysis) and convergent validity with negative impacts. RESULTS: Overall, 37% of participants reported experiencing any IPV and 29% experienced any IPV after age 18. Women experienced more frequent IPV, more acts of IPV and more negative impacts than men (p<0.001 for all comparisons). The IPV measure showed high internal consistency (α=0.95), strong evidence for unidimensionality and was highly correlated with negative impacts (r=0.579, p<0.001). CONCLUSIONS: The prevalence of IPV victimisation in the ALSPAC cohort was considerable for both women and men. The strong and consistent gender differences in the frequency and severity of IPV suggest clinically meaningful differences in experiences of this violence. The ALSPAC measure for IPV victimisation was valid and reliable, indicating its suitability for further aetiological investigations.
epidemiology, mental health, public health, social medicine
Long-term trends in child maltreatment in England and Wales, 1858-2016: an observational, time-series analysis.
2019
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Journal article
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Lancet Public Health
BACKGROUND: It is unclear whether child maltreatment is increasing or decreasing in England and Wales. More evidence is needed, from multiple sources and over longer periods of time, to explore trends in child maltreatment. We investigated whether the annual incidence of child maltreatment has changed over time, using official record data and time-series methods to establish long-term trends. METHODS: In this observational time-series analysis, we used six data sources (Government records for child mortality, police-recorded child homicides, crimes against children, child protection, and children in care; and NSPCC data) to estimate the incidence of child maltreatment in England and Wales and examine long-term trends. We included nationally representative data that could estimate the incidence of child maltreatment for more than 25 years. Our primary outcomes were the number of victims (age <20 years) or perpetrators (age >16 years) of child maltreatment per 12-month period in England, including or excluding Wales. We fitted Poisson regression models with year as the exposure and the number of victims or perpetrators of child maltreatment as the outcome (adjusted for population age-structure and size). When a linear trend was not appropriate, we fitted generalised additive models with penalised splines to visualise trends. FINDINGS: The incidence of child mortality by homicide or assault decreased by 90% (2·7 per 100 000 children) between 1858 and 2016 and the incidence of people guilty of child cruelty or neglect decreased by 83% (6·7 per 100 000 adults) between 1893 and 2016, whereas child protection registrations increased by 182% (328·7 per 100 000 children) between 1988 and 2016. Crimes against children and children entering care increased between 2000 and 2016. In 2016, 40 children died by homicide, with twice as many adolescent (15-19 years) deaths than infant (age <1 year) deaths. In 2016, 67 700 children were placed on the child protection register and neglect and emotional abuse were the most common reasons. INTERPRETATION: Although long-term trends have decreased, child maltreatment remains a major public health problem in England and Wales. Further research is needed to establish whether adolescents are a particularly vulnerable age group and whether neglect and emotional abuse are increasing. Future child protection policies and practices should respond to these areas of growing need. FUNDING: Andrew W Mellon Foundation and Clarendon through The Oxford Research Centre in the Humanities, Oxford.
Long-term trends in child maltreatment in England and Wales: A time series analysis of official record data from 1858 to 2016
2019
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Journal article
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Lancet Public Health
Are long-term trends in child maltreatment decreasing in England and Wales? A time-series analysis of official record data, 1858-2016
2018
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Conference paper
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LANCET
PA12-2-2323 Associations between firearm laws and firearm homicides in US cities: a bayesian space-time analysis
2018
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Conference paper
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Abstracts
Regional differences in the impact of the "Stand Your Ground" law in Florida.
2018
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Journal article
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Prev Med
In October 2005, Florida relaxed restrictions on the use of lethal force in self-defense with the Florida stand your ground law (SYG). We examined whether and how the impact of the Florida SYG varied based on the demographic and economic conditions of each of its counties. Using data from the Florida Universal Crime Reports on homicides and firearm homicides from 1999 to 2014, we found that the impact differed significantly by county urbanization, unemployment, and pre-law homicide rates. The largest increases in homicide and firearm homicide occurred in proportionally safer, richer, and less ethnically diverse suburban counties. These findings reveal that the law may have had the opposite effect than intended, and more strongly impacted counties considered safe, suburban and economically successful.
OP48 #A systematic review and theory synthesis for the impact of foreign aid on HIV/AIDS in sub-saharan africa
2018
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Conference paper
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Oral presentations
iCoverT: A rich data source on the incidence of child maltreatment over time in England and Wales
2018
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Journal article
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PLoS ONE
A cumulative meta-analysis of the effects of individual physical activity interventions targeting healthy adults.
2018
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Journal article
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Obes Rev
Despite a large and increasing evidence base on physical activity interventions, the high rates of physical inactivity and associated chronic diseases are continuing to increase globally. The purpose of this cumulative meta-analysis was to investigate the evolution of randomized controlled trial evidence of individual-level physical activity interventions to asses if new trials are contributing novel evidence to the field. Through a two-staged search process, primary studies examining the effects of interventions targeted at increasing physical activity within healthy adult populations were pooled and selected from eligible systematic reviews. Cumulative meta-analyses were performed on effect sizes immediately post-intervention (n = 62), and for long-term behaviour change (≥12-month post-baseline; n = 27). Sufficiency and stability of the evidence was assessed through application of pre-published indicators. Meta-analyses suggest overall positive intervention effects on physical activity. The evidence base for effectiveness immediately post-intervention reached levels of sufficiency and stability in 2007; and for long-term follow-up in 2011. In the time since, intervention effectiveness has not substantially changed, and further trials are unlikely to change the direction and magnitude of effect. Substantial evidence exists demonstrating that physical activity interventions can modify individual behaviour in controlled settings. Researchers are urged to shift focus towards investigating the optimization, implementation, sustainability and cost-effectiveness of interventions.
Risk and Protective Factors for Intimate Partner Violence Against Women: Systematic Review and Meta-analyses of Prospective-Longitudinal Studies.
2018
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Journal article
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Am J Public Health
BACKGROUND: The estimated lifetime prevalence of physical or sexual intimate partner violence (IPV) is 30% among women worldwide. Understanding risk and protective factors is essential for designing effective prevention strategies. OBJECTIVES: To quantify the associations between prospective-longitudinal risk and protective factors and IPV and identify evidence gaps. SEARCH METHODS: We conducted systematic searches in 16 databases including MEDLINE and PsycINFO from inception to June 2016. The study protocol is registered with PROSPERO (CRD42016039213). SELECTION CRITERIA: We included published and unpublished studies available in English that prospectively analyzed any risk or protective factor(s) for self-reported IPV victimization among women and controlled for at least 1 other variable. DATA COLLECTION AND ANALYSIS: Three reviewers were involved in study screening. One reviewer extracted estimates of association and study characteristics from each study and 2 reviewers independently checked a random subset of extractions. We assessed study quality with the Cambridge Quality Checklists. When studies investigated the same risk or protective factor using similar measures, we computed pooled odds ratios (ORs) by using random-effects meta-analyses. We summarized heterogeneity with I2 and τ2. We synthesized all estimates of association, including those not meta-analyzed, by using harvest plots to illustrate evidence gaps and trends toward negative or positive associations. MAIN RESULTS: Of 18 608 studies identified, 60 were included and 35 meta-analyzed. Most studies were based in the United States. The strongest evidence for modifiable risk factors for IPV against women were unplanned pregnancy (OR = 1.66; 95% confidence interval [CI] = 1.20, 1.31) and having parents with less than a high-school education (OR = 1.55; 95% CI = 1.10, 2.17). Being older (OR = 0.96; 95% CI = 0.93, 0.98) or married (OR = 0.93; 95% CI = 0.87, 0.99) were protective. CONCLUSIONS: To our knowledge, this is the first systematic, meta-analytic review of all risk and protective factors for IPV against women without location, time, or publication restrictions. Unplanned pregnancy and having parents with less than a high-school education, which may indicate lower socioeconomic status, were shown to be risk factors, and being older or married were protective. However, no prospective-longitudinal study investigated the associations between IPV against women and any community or structural factor outside the United States, and more studies investigated risk factors related to women as opposed to their partners. Public health implications. This review highlights that prospective evidence for perpetrator- and context-related risk and protective factors for women's experiences of IPV outside of the United States is lacking and urgently needed to inform global policy recommendations. The current evidence base of prospective studies suggests that, at least in the United States, education and sexual health interventions may be effective targets for preventing IPV against women, with young, unmarried women at greatest risk.
David would welcome applications for D.Phils from students who are committed to policy-relevant research on violence and injury prevention. He would be particularly interested to hear from students who are interested in examining the impact of structural level interventions, using quasi-experimental or other novel methodological designs.
